Refrigerating apparatus



April 17, 1934. PHlLlPP 1,955,087

REFRIGERATING APPARATUS I Filed June 27, 1952- I c 5 8 74 v 12: '1 i2 1 :9

INVENTOR. MMae/m" 4. PHIL/PP ATTORNEY.

Patented Apr. 17, 1934 REFRIGERATING APPARATUS Lawrence A. Philipp, Detroit, Mich, assignor to .Kelvinator Corporation, Detroit, Mich, a corporation of Michigan Application June 27, 1932, Serial No. 619,429

7 @laims.

.This invention relates to refrigerating appa= ratus and more particularly to refrigerating apparatus of the multiple temperature type.

Heretofore it has been the practice to provide a single refrigerant evaporator for freezing ice cubes and the like and for cooling the circulating air in the food storage compartment of a refrigerator cabinet. This arrangement has .been found to be unsatisfactory for the reason that m the placing of large quantities of warm substances in the evaporator to be frozen materially affected the temperatures in the food storage compartment. In addition it was necessary to operate the evaporator at temperatures below freezing in order to freeze ice cubes therein. This caused the collection of frost and ice on the outer surface of the evaporator due to the deposit of moisture thereon from the circulating air in the food compartment. Under these conditions it was necessary to periodically defrost the evaporator. Other arrangements for refrigerating cabinets included the use 'of one evaporator for cooling the food storage compartment and another evaporator for freezing purposes. In refrigerating systems ofthis type, the

evaporator used for cooling the food compartment was operated at temperatures sufficiently low enough for cooling the compartment to'predetermined temperatures by natural air convecv tion. Under these conditions it has been found that the evaporator used for cooling the food compartment'readily collected ice and frost on its outer surface and had to be periodically defrosted.

By the present invention I have avoided the above difficulties by providing a refrigerant evaporator of small heat capacity which may be operated at temperatures above that which would cause the collection of frost and ice thereon and 40 which is insufficient for cooling the food storage compartment to the proper temperature for the preservation of food articles stored therein by natural air convection, and for thepurpose of cooling said compartment to the-proper temperatures I have, provided forced air convection means operable in response to changes in temperatures in the food compartment for. circulating air about the evaporator for maintaining the desired temperaturesin-the compartment.

improved arrangement within a refrigerator cabinet for cooling a food storage compartment and for the freezing of ice cubes and thelike.

Another object of my invention is to freeze ice cubes and the like in a refrigerator cabinet by the use of a relatively large heat capacity refrigerant evaporator and to refrigerate a food storage compartment of the cabinet by the use of a relatively small heat capacity refrigerant evaporator which operates at temperatures Another object of my invention is to provide an (Ci. 62-lll2) above the freezing point of water and to employ forced air convection means for circulating air about said small heat capacity evaporator in said food compartment and to control the operation of refrigerant circulating means associated with said evaporators in response to changes in temperature of the large heat capacity evaporator and to control the operation of the forced air convection means in response to changes in temperature in the foodstorage compartment.

Another object is to maintain the aforesaid relatively small heat capacity evaporator com pletely flooded with liquid refrigerant so as to avoid changes in the refrigerating effect thereof due to the operation of the condensing unit in response to a demand for refrigeration by the relatively large heat capacity evaporator.

Other objects and advantages of the present invention willbe readily apparent from the following description and by reference to the accompanying drawing.

In the drawing: i

The figure in the drawing is a view partly in cross section and partly in elevation of a refrigerating apparatus embodying features of my invention.

Referring to the drawing the numeral 20 designates in general a refrigerator cabinet having a food storage compartment 22, a freezing compartment 24 and a machine compartment 26. An inner metallic lining member 28 is provided for forming the inner walls of the food storage "m"- partment 22. Preferably the liner 28 is prov ca; with a coating of vitreous enamel such, for e ample, as porcelain. An inner metallic lining member 30 is provided for forming the inner walls of the freezing compartment 24. Suitable insulation 32 is interposed between the inner Til lining members 28 and 30 and an outer metallic I casing 34 and between the top wall of the lining members 28 and 30 andthe metallic member 35 which forms the base of the machine compartment 26. Thus it will be noted that the food storage compartment and the freezing compartment are insulated from one another and from the machine compartment 26.

Within the cabinet 20 there is disposed a refrigerating system which comprises ingeneral a refrigerant circulating or condensing. element 40 disposed in the machine compartment, a refrigerant evaporator 42 disposed in the foodstorage compartment and a refrigerant evaporator 44 in compartment 24. v I

Preferably the, evaporator 441s of relatively large heat capacity and is used for freezingice cubes and the like. Suitable ice'trays (not shown) may be provided for insertion within the interior of the evaporator; The evaporator 44 is pr eferably of the flooded type and includes a.,U-

shaped wall structure 45 provided with a pair of headers 47 disposed adjacent the top of the evaporator. The evaporator 44 also includes a refrigerant header 50 disposed at the rear of the evaporator and in open communication with the bottom of the U-shaped member of the evaporator for supplying liquid refrigerant to the U- shaped member. Liquid refrigerant is supplied to the header 50 through conduit 54. Gaseous refrigerant is withdrawn from the header 50 through a conduit 56. Gaseous refrigerant from the headers 47 enters the header 50 through conduits 58 which are disposed above the level of liquid refrigerant in the header 50.

The evaporator 42 is preferably of relatively small heat capacity and is used for refrigerating the food compartment. The evaporator is formed of a single conduit 60 coiled to form a serpentine passage for refrigerant. A plurality of heat absorbing fins 62 are associated with the conduit 60. Liquid refrigerant is supplied to the evaporator 42 through conduit 65. Gaseous refrigerant leaves the evaporator 42 through conduit 67. Preferably the evaporator 42 is adapted to be completely filled with liquid refrigerant at all times so as to prevent noticeable variation in pressor withdraws the gaseous refrigerant from the header 50 through vapor conduit 56, compresses the gaseous refrigerant and delivers it to a condenser 72 wherein it is liquefied and from which it is delivered to a high side float 74. Liquid refrigerant is delivered from the high side float to the header 50 through conduit 54. A fan 75 actuated by the motor contained in casing 70 is used for cooling the condenser '72.

Preferably the heat capacity of the evaporator 42 is such that the evaporator is insufficient for cooling the compartment to temperatures within a range of 33 Fahrenheit to 50 Fahrenheit by natural air convection. Thus the evaporator without the aid of additional means would be insufficient for refrigerating foods stored in the foddcompartment to the proper temperatures for preserving same. However, I have provided forced air convection means for increasing the heat transfer in the food compartment to the evaporator for causing the evaporator to refrigerate the food compartment to the proper temperatures. This forced air convection means comprises in general a fan located in the food compartment directly over the evaporator 42 and a motor 82 for driving thefan 80. The motor 82 is located preferahly in the machine compartment.

In order to control the temperatures within- 42 may be operative at a temperature but slightly below the temperature to which it is desired to refrigerate the compartment 22. The temperature at which it is desired to maintain compartment 22 may be for example 45 Fahrenheit which is above that which would cause the col- .87 or for any other reason which would cause a slight formation of frost on the evaporator 42, this slight, layer would immediately melt therefrom when the fan, 80 ceases operation.

In order to provide means for controlling the operation of the condensing unit I have provided a fluid containing bulb 95, the fluid contained therein being expansible and contractible in response to changes in temperatures in the evaporator 44. The bulb is operatively associated with an automatic switch 97 for connecting and disconnecting the motor contained in casing 70 to power mains 98 in response to changes in temperatures in evaporator 44. Any suitable switch of the types well known in the art having the above characteristics maybe provided for this purpose. By this arrangement the placing of i a large amount of warm substances within the evaporator 44 to be frozen, the heat will immediately be transferred to the evaporator 44 and bulb 95 to start the operation of the condensing unit. This provides for quick ice freezing and the like.

In view of the fact that the evaporator 42 is completely filled with liquid refrigerant the operation of the condensing unit in response to changes in temperatures in the evaporator 44,

will have very little, effect on the refrigerating effect of evaporator 42. However, what effect it might have at this time is readily compensated for by the temperature controlled fan 80. In other words, the fan ceases operation when the temperature in compartment 22 reaches a predetermined low point and starts operation when the temperature in the compartment 22 attains a predetermined high point.

From the foregoing it will be noted that I have provided a new and improved arrangement for refrigerating a food storage compartment of a refrigerator cabinet and that I have provided for the rapid freezing of ice cubes in large quantitles by the same refrigerating system. It wlll invention or from the scope of the appended claims.

What I claim as my invention is:

1. Refrigerating apparatus comprising, in com-.

bination, means providing a food storage com.- partment and a second compartment, a low temperature refrigerant evaporator disposed in said second compartment for freezing substances, a refrigerant evaporator disposed for cooling said air therein to vary the heat absorbing characteristics of said evaporator to maintain said predetermined temperatures within said range irrespective of variations in the operation of said means.

2. Refrigerating apparatus comprising, in combination, means providing a food storage compartment and a second compartment, a low temperature refrigerant evaporator disposed in said second compartment for freezing substances, a refrigerant evaporator disposed for cooling said food compartment, said latter refrigerant evaporator having a capacity insuflicient for cooling said food compartment to predetermined temperatures within-a range of 33 F. to 50 F. at least under all conditions of operation by natural air convections, means for, supplying liquid refrigerant to and for withdrawing gaseous refrigerant from said evaporators, a single control device responsive to changes in temperatures in said second compartment for controlling the operation of said means, and a temperature responsive fanfor circulating air about said food compartment and evaporator located for cooling air therein to vary the heat absorbing characteristics of said evaporator to maintain said predetermined temperatures within said range irrespective of variations in the operation of said means.

3. Refrigerating apparatus comprising, in combination, means providing two compartments, a low temperature refrigerant evaporator disposed in one of said compartments, a relatively high temperature refrigerant evaporator in open communication with said low temperature evaporator and being disposed for cooling circulating air in the second compartment, a refrigerant condensing element operatively associated with said evaporators, means responsive to changes in conditions in the system for,controlling the operation of said condensing element, and means respon-j sive to changes in temperatures within said second compartment including a fan operable to cir- .culate air about said high temperature evaporator and second compartment for maintaining the temperatures therein within predetermined limits irrespective ofavariations in temperatures within said first named compartment or variations in operating'periods of said condensing element. r

4. Refrigerating apparatus comprising, in combination, means providing a freezing compartment and a food storage compartment, a large heat capacity refrigerant evaporator-disposed in said freezing compartment, a'relatively small heat capacity refrigerant evaporator disposed for cool- I ing said food compartment, a refrigerant condensing element including a compressor, means connecting the outlet end of said small heat-capacity evaporator in open communication with the intake of said compressor so that vaporized refrheranti'sfreetopassatalltimesto thempressor, said small heat capacity refrigerant evaporator being insufflcient to cool said compartment to predetermined temperatures within a range of 33 F. to 50 F. by natural air convection, means including a fan responsive to changes in temperatures within said food compartment for circulating the air in said compartment about said small capacity evaporator to increase evaporation therein for maintaining said predetermined temperatures within said range, and means responsive to changes in a condition in said large capacityevaporator for controlling the operation' of said condensing element.

partment and a second compartment, a low'tem- 5. Refrigerating apparatus comprising, in combination, means providing a food storage comperature refrigerant evaporator disposed in said a second compartment for freezing substances, a refrigerant evaporator disposed for cooling said food compartment, said latter refrigerant evaporator having a capacity insuilicient for cooling said food compartment to predetermined temperatures within a range of 33 F. to 50 F. at least under all conditions of operation by natural air convection and so that frost or ice does not accumulate thereon at least part of the time,,

means for supplying liquid refrigerant to and for withdrawing gaseous refrigerant from said evap-,

orators, a single control device responsive to changes in a condition in said low temperatureevaporator for controlling the operation. of said means, and a temperature responsive fan for circulating air about said food compartment and evaporator located for coolingair therein to vary the heat absorbing characteristics of said evaporator to maintain said predetermined temperatures within said range irrespective of variations in the operation of said means.

6. Refrigerating apparatus comprising, in combination, means providing a food compartment and a second compartment, a low temperature refrigerant evaporator disposed in said second compartment for freezing substances, a relatively high temperature refrigerant evaporator disposed for cooling said food compartment, refrigerant header means connected in open communication with each of said evaporators for receiving gaseous refrigerant therefrom, means for supplying liquid refrigerant to and for withdrawing gaseous refrigerant from said header means, a thermostat'responsive to changes in temperatures in said header means for controlling the operation of said means, and a temperature responsive fan for circulating air about said food compartment and over said relatively high temperature evaporator.

'7. Refrigerating apparatus comprising, in combination, means providing a food compartment and a second compartment, a low temperature refrigerant evaporator disposed in said second compartment for freezing substances, a relatively high temperature refrigerant evaporator disposed for cooling said food compartment, refrigerant header means connected in open communication with each of said evaporators above and below the level of liquid refrigerant in said evaporators, means for supplying liquid refrigerant to and for withdrawing gaseous refrigerant from said header means, a thermostat responsive to changes in temperatures in said header means for controlling the operation of said means, and artemperature responsive fan for circulating air about said food compartment and said relatively high temperature evaporator.

. A. PHILIPP. 

